1. Field of the Invention
This invention relates to a device for rapidly removing dew formed on a metal portion on a tape running path in a video tape recorder.
2. Description of the Prior Art
In a video tape recorder (herein referred to as VTR), dew is produced on a part of the tape running path by moving the device from a low temperature location to a high temperature room in which heating has been made or by rapidly increasing the room temperature by initiating the heating in a cold room, and this will result in inability of the tape running to cause a trouble of cutting or damaging the tape.
FIG. 1 shows an example of a known VTR tape running mechanism in which a video tape cassette is located in its loaded-in position. During the recording or playback mode, a video tape is moved as is shown by a dotted line, while it passes around about a half of a peripheral surface of the tape guide cylinder 3 provided with a rotary magnetic head. At this time, a known erase head 4 and an impedance roller 5 are moved from their retracted positions to positions shown by dotted lines and at which they are brought into engagement with the video tape 2. In a normal temperature condition, the tape will be moved without hindrance. However, if the VTR is moved in winter, for example, from a location of a temperature of 0.degree. C. to another location of a temperature of about 20.degree. C., the temperature of parts of the mechanism in the VTR having a relatively large heat capacity, such as the cylinder 3, the full erase head 4, the impedance roller 5, an audio control head 6 and pinch roller 7, can not be rapidly increased to cause a difference between the temperature of these parts and the ambient temperature thereby producing dew on surfaces of the parts and thus the video tape 2 during running movement tends to be stuck by the dew to the surfaces of the parts, such that the tape 2 is wound around, for example, the cylinder 3 rotating at a high speed to cause the severance of the tape, or stuck to the full erase head 4 to cause the inability of the tape running operation. Therefore, the VTR ought not to be operated under such a condition that dew is produced on its parts. The dew will disappear, if the VTR is left as it is, but a relatively long time, such as several hours, will be required. In order to shorten the time required for the disappearance of the dew, in some kinds of VTR, there is provided a small type of a blower device for directing air to the tape running system for drying it when dew is produced. However, there are drawbacks in that the blower device must be of a fairly small type having a restricted air discharge and a restricted air blowing range, and in that there is no need to mount such blowers in all of the VTR, because the troubles due to the dew are mainly caused in a cold country in winter and almost not caused in summer or in a hot country and thus the provision of the blowers in all of the VTR will increase the cost of the VTR.
In another type of the VTR, a panel above the cylinder is detachably provided in a circular section into which a specific blower is inserted to direct air to the interior of the VTR. However, this arrangement is disadvantageous in that the fixation of the blower is not easy and the VTR does not have a fine external appearance.